As we all know the gauges that come installed with our RV's are not very accurate. My fresh water gauge may read full and I only have 1/2 or 3/4 of a tank. I am looking for a water flow gauge to tell me how much water I am putting in my fresh water tank when I fill it, so I know how close to full I really am. I would also like to use it in line with my city water connection to monitor how much water has gone thru my water filters. Does anyone have any water flow gauges that they would recommend?